Prior art chemical vapor deposition (CVD) processes for the production of diamond films include DC torch, microwave, hot filament and rf plasma techniques. Generally, the prior art techniques deposit diamond over a rather small area and/or at slow deposition rates, with the result that film costs have been high.
A recent patent application (U.S. Ser. No. 08/361,667, filed Dec. 22, 1994) teaches a novel method and apparatus for the generation of a large-area high-frequency induction plasma and for the presentation to that plasma of a large-area work surface onto which diamond can be deposited in large areas and at reasonably fast rates. The diamond is deposited in a chamber which is encircled by high frequency current on paths that are substantially transverse to, and arrayed along, the axis of the chamber. A plasma sheath generated within the chamber surrounds and extends along the axis of the chamber and conforms to the sidewalls of the chamber. A work surface also extends along the axis of the chamber and is exposed to the plasma sheath, preferably at the outer boundary of the plasma sheath along the chamber sidewalls.
In a specific method and apparatus disclosed in the recent patent application, the chamber comprises dielectric walls (for example, made from quartz) to allow penetration of magnetic and electric fields into the chamber. The present invention extends the benefits realized from the earlier invention by providing a chamber structure (for example, made from metal) that is highly durable, even at elevated temperatures developed during operation of the system at a high power level.